1. Field of the Invention
This invention relates to improvements in side door hinge mechanism utilizing a quadric crank chain in a motor vehicle.
2. Description of Related Art
Typically, the side door in a motor vehicle, such as a passenger car is installed in a manner to be rotatable about a hinge affixed to a vehicle body for opening or closing. In order to allow an occupant of the motor vehicle to open or close the side door for getting in or out of the motor vehicle, a door opening angle corresponding to the total length of the side door is required. At this time, when a space at the side of the motor vehicle is small, there are many situations where it is difficult for the occupant to get in or out of the vehicle because the side door cannot be opened sufficiently.
To overcome this difficulty, as has been disclosed in many publications such for examples as U.S. Pat. Nos. 3,074,755 and 3,095,600 and Japanese Utility Model Laid Opens Nos. 55-101,263 and 57-46,014, there has been proposed a side door hinge mechanism utilizing a quadric crank chain mechanism.
Furthermore, as proposed in U.S. patent application Ser. Nos. 611,149, 611,216 and 611,339 as shown in FIG. 1, there may be proposed a side door hinge mechanism in a motor vehicle, wherein a quadric crank chain comprises: a rotary link 4 interconnecting a vehicle body 2 and a side door 3 between rotary members 2A and 3A; a rotary link 5 also interconnecting the vehicle body 2 and the side door 3 between rotary members 2B and 3B; a body portion extends between the two rotary members 2A and 2B on the vehicle body 2; and a door portion extends between the two rotary members 3A and 3B along the side of the side door 3.
In the drawing, designated at 6 is a front pillar, 7 a front wheel and 8 a movable fender capable of rocking with the rotary link 4.
In the side door hinge mechanism utilizing the above-described quadric crank chain, a required space at the side of the door can be reduced while sufficient space for feet of the occupant is maintained. As a consequence, even when the space at the side of the door is small, the occupant can open or close the side door 3 to get in or out of the vehicle.
However, shown in FIG. 2 for example, as the outer shapes for the vehicle body of passenger cars and the like produced in recent years reflects a styling in which a door glass 9 portion is considerably inclined and curved upwardly and inwardly in the widthwise direction of the vehicle body. Because of this, even if there is provided the aforesaid side door hinge mechanism utilizing the quadric crank chain, the top end portion of a door frame of the side door 3 or the top end portion of a door glass 9 interferes with an occupant 10 when the occupant gets in or out of the vehicle. As a result the occupant 10 must considerably bend his upper body, in order to get in or out of the vehicle.